We all need them, and it’s got nothing to do with looking at celebrities.
In essence a star rating describes the amount of energy that your building uses as measure in mega joules per hour. The scale has a range of between one and 10 stars. Multiple organizations promote this with competitions to see who can get a perfect 10 star building, one of which is the BDAV who run a yearly competition to improve the overall industry knowledge of how to do this.
A six star rating is what is required in Australia at the moment for residential, and energy requirements for other building typologies are quickly catching up.
This is generally not hard to achieve. One effect though is that you will need to be wise about how you go about composing a building. This is where we are experts in designing buildings that perform well and reach 6 stars and beyond.